In the much-anticipated ruling, the court said Kansas' poor school districts were harmed when the state made the decision to cut certain payments when tax revenues declined during the Great Recession.

The Supreme Court also sent the case back to district court for more review to "promptly" determine what the adequate amount of funding should be, but didn't set a deadline for a hearing. It did, however, set a July 1 deadline for legislators to restore money for two funds aimed at helping poorer districts with capital improvements and general school operations.

The case has broader implications beyond the classroom: Kansas enacted sweeping cuts to income taxes in 2012 and 2013 championed by Gov. Sam Brownback that have reduced the amount of available resources to comply with a court order.

The lawsuit was filed in 2010 on behalf of parents and school districts who argued the state had harmed students because spending cuts resulted in lower test scores. State attorneys maintained that legislators did their best to minimize cuts to education.

Friday's decision has been in the works since the state appealed after a three-judge panel in Shawnee County District Court said in January 2013 that the lawsuit was valid. Because no issues involving the U.S. Constitution were raised, there's no appeal to the U.S. Supreme Court.

In the lawsuit, attorneys representing four school districts and parents alleged that Kansas reneged on promises made in 2006 to provide a certain level of funding the Kansas' public schools, namely that the failure to provide money for classroom instruction has harmed the state's education system - including programs aimed at helping poor and minority students.

In recent years, school districts have trimmed their staffs, cut after-school programs and raised fees for parents. Classrooms became more crowded.

State attorneys had said legislators did the best they could to maintain education spending among the reduced available revenues during the recession, pointing to efforts to raise the state sales tax rate in 2010 and the reliance on federal stimulus funding to keep spending stable.

Legislators delayed any decisions on school funding until the high court made a final judgment.